Merge pull request TheAlgorithms#8 from dcariotti/patch-1

Added linkedlist

Linkedlist.go

@@ -0,0 +1,102 @@
+package main
+
+import "fmt"
+
+/* v is the value of node; next is the pointer to next node */
+type node struct {
+	v int
+	next *node
+}
+
+/* first node, called head. It points from first node to last node */
+var head *node = nil
+
+func (l *node) pushFront(val int) *node {
+	/* if there's no nodes, head points to l (first node) */
+	if head == nil {
+		l.v = val
+		l.next = nil
+		head = l
+		return l
+	} else {
+		/* create a new node equals to head */
+		nnode := new(node)
+		nnode = head
+		/* create a second node with new value and `next -> nnode`
+		*  is this way, nnode2 is before nnode
+		*/
+		nnode2 := &node {
+			v: val,
+			next: nnode,
+		}
+		/* now head is equals nnode2 */
+		head = nnode2
+		return head
+	}
+}
+
+func (l *node) pushBack(val int) *node {
+	/* if there's no nodes, head points to l (first node) */
+	if head == nil {
+		l.v = val
+		l.next = nil
+		head = l
+		return l
+	} else {
+		/* read all list to last node */
+		for l.next != nil {
+			l = l.next
+		}
+		/* allocate a new portion of memory */
+		l.next = new(node)
+		l.next.v = val
+		l.next.next = nil
+		return l
+	}
+}
+
+func (l *node) popFront() *node {
+	if head == nil {
+		return head
+	}
+	/* create a new node equals to first node pointed by head */
+	cpnode := new(node)
+	cpnode = head.next
+
+	/* now head is equals cpnode (second node) */
+	head = cpnode
+
+	return head
+}
+
+func (l *node) popBack() *node {
+	if head == nil {
+		return head
+	}
+	/* create a new node equals to head */
+	cpnode := new(node)
+	cpnode = head
+
+	/* read list to the penultimate node */
+	for cpnode.next.next != nil {
+		cpnode = cpnode.next
+	}
+	/* the penultimate node points to null. In this way the last node is deleted */
+	cpnode.next = nil
+	return head
+}
+
+func main() {
+	lista := new(node)
+	lista.pushBack(25).pushBack(24).pushBack(32) /* lista: 25 24 32 */
+	lista.pushBack(56) /* lista: 25 24 32 56 */
+	lista.pushFront(36) /* lista: 36 25 24 32 56 */
+	lista.popFront() /* lista: 25 24 32 56 */
+	lista.popBack() /* lista: 25 24 32 */
+
+	/* read the list until head is not nil */
+	for head != nil {
+		fmt.Printf("%d ",head.v)
+		head = head.next /*head points to next node */
+	}
+}